The invention concerns a magnetic valve with a manual override in accordance with the generic part of Claim 1.
Such a magnetic valve is known, for example, from DE 39 41 643 C1; said valve can be actuated by means of mechanical manual operation without a supply of current so that the switching state of the magnetic valve is no longer dependent on the flow of current. In this way reliable actuation is enabled before a system also operates “electrically,” thus manual operation of actors such as a cylinder is achieved. This can also be advantageous during servicing. With the usual latching manual overrides, the magnetic core or the valve element remains in the operating position set by the manual override until unlatching takes place. This can lead to problems, since if one forgets to reset the manual override, the valve can take the wrong valve setting in subsequent operation. If a large number of magnetic valves is used, for example in a large industrial plant, it is then very difficult to find the magnetic valve or valves in which the manual override was not reset.
Usually one can detect the pushed-in position of the actuating element of the manual override visually, but only upon close inspection, so that the corresponding reexamination of a large number of magnetic valves is very complicated and time-consuming. Additional sensors, in particular position sensors, for detecting the position of the valve element make a valve complicated and expensive.